1. Field of the Invention
The present invention relates to a printing method and a transport member.
2. Description of the Related Art
In inkjet printing methods, screen priming methods and offset printing methods and the like, following application and printing of an ink onto a recording medium, the recording medium is sometimes transported without first performing a fixing treatment or the like on the primed surface, with the ink in an undried state. In a paper ejection step performed immediately following printing, in those cases where the recording medium is transported by frictional contact using transport rollers or the like, there is a possibility that when a transport roller contacts the printed surface of the recording medium, the ink on the recording medium may adhere to the transport roller, and the ink adhered to the transport roller may then be transferred to another position on the same recording medium, or onto a following recording medium, generating so-called transfer staining.
Patent Document 1 proposes a printing apparatus which, in order to suppress the occurrence of staining caused by transfer of an ink to a rotating body used for transporting a primed paper, has a cleaning member which is pressed into contact with the outer peripheral surface of the rotating body to clean the ink adhered to the outer peripheral surface of the rotating body. However, problems arise in that installing a cleaning member has an associated cost, and also requires installation space inside the printing apparatus.
Patent Document 2 proposes a sheet-feeding roller device in which, during transport of a sheet on which an image has been formed, in order to prevent the uncured ink from adhering to a feed roller and the following sheet then being stained by the transfer of ink from the roller, a plurality of protections are formed on the outer peripheral surface of one of a pair of rollers, and a multitude of fine projections are formed on the outer peripheral surface of the other roller. However, when the rollers contact the sheet via these projections, there is a possibility that slipping may occur during sheet feeding, resulting in a delay in the sheet feed.
On the other hand, inks can be broadly classified into aqueous inks and non-aqueous inks. Non-aqueous inks are less likely to cause curling or cockling of the recording medium such as paper, thereby facilitating transport of the recording medium, and are therefore suited to high-speed printing. A non-aqueous ink is a penetration-drying type ink, meaning the ink itself does not dry and solidify, but rather penetrates into the recording medium such as paper and then dries. Because non-aqueous inks require a comparatively long time to dry, transfer staining tends to occur reasonably frequently when the recording, medium is transported by transport, rollers following printing. Further, in those cases where transport rollers made of resin are used, a problem arises in that the transport rollers may be attacked by the non-aqueous ink, causing a deterioration in the durability of the rollers.    [Patent Document 1] SP 2004-138234 A    [Patent Document 2] JP 2007-320714 A
An object of the present invention is to provide a printing method and a transport member which prevent transfer staining by the transport member and improve the ink resistance of the transport member.